1. Field of the Invention
The present invention relates to a silicone resin composition, an encapsulating layer, a reflector, and an optical semiconductor device, in particular to a silicone resin composition, an encapsulating layer composed of the silicone resin composition, a reflector containing the silicone resin composition, and an optical semiconductor device including these.
2. Description of Related Art
Conventionally, a silicone resin excellent in transparency has been used as an encapsulating material for encapsulating optical semiconductor elements such as a light-emitting diode (LED). Such a silicone resin is liquid at room temperature. The silicone resin is applied to an optical semiconductor element, and then cured by heating, thereby encapsulating an optical semiconductor element.
Furthermore, in view of storage stability and handleability, a silicone resin that is solid at room temperature is also used. As such a solid silicone resin, for example, Japanese Unexamined Patent Publication No. 2000-154252 has proposed a silsesquioxane-containing polymer obtained by allowing pentacyclo[9.5.1.13.9.15.15.17.13]octasiloxane to react with 1,3-divinyltetramethyldisiloxane.
Also, Japanese Unexamined Patent Publication No. 2002-69191 has proposed a polysiloxane obtained by allowing hydrogenated octasilsesquioxane to react with disilanol.
The encapsulating materials proposed in Japanese Unexamined Patent Publication No. 2000-154252 and Japanese Unexamined Patent Publication No. 2002-69191 are plasticized by heating, thereby encapsulating optical semiconductor elements.